(a) Field of the Invention
The invention relates to a nebulizer assembly, and more particularly, to a nebulizer in which an oscillator driver is provided with an aerosol excitation device at the power output terminal thereof, and the aerosol excitation device is adjacently disposed to a liquid delivery device for supplying an impingement baffle of the aerosol excitation device with micro liquid bodies having formed tension liquid membranes, thereby acting energy completely onto the micro liquid membranes for nebulizing aerosol particles and further achieving aimed nebulization as well as avoiding any unnecessary loading.
(b) Description of the Prior Art
A nebulizer assembly particularly applied in aerosol nebulizers comprises an oscillator driver for loading an aerosol excitation device provided on an acting plane, and a liquid delivery device adjacently disposed to the aerosol excitation device for supplying an impingement baffle of the excitation device with liquid membranes for further micro loading and impingement. Therefore the energy of the excitation device is totally acted onto the liquid bodies in micro units and maximizes the efficiency thereof.
In the early days, prior arts for producing aerosols include forming aerosols from steam by heating in order to provide humidifying or medical auxiliary equipment applications. However, energy required for forming steam by heating is rather significant, and heating is often unfavorable for controlling medical properties of medical materials because temperature changes are liable to bring chemical reactions. Later, the prior art is improved by ultrasonic actions of mechanical oscillation to have aerosols of liquid particles break away from liquids or medical solutes by oscillation.
In conventional ultrasonic oscillation, the oscillation energy thereof comes into contact with the surface of a liquid and breaks micro liquid particles formed by excitation away from the liquid. A fan then blows and forwards the aerosol of micro particles to the user's terminal. Nevertheless, such method of ultrasonic employs the oscillator for loading the impingement baffle for further direct contact with the liquid surface, and hence the oscillator is necessarily large in size and power in order to conduct energy within the liquid for stimulating the liquid surface. Also, the impingement baffle is in direct contact within the liquid, and thus the produced oscillation energy is forced to accept the unavoidable contact loss of the liquid. As a result, a large power that relatively consumes significant energy is required. Furthermore, due to various amounts and volumes of the remaining liquid, the waves of oscillation produce aerosol particles having different sizes that even need blowing by fans, and the oscillator in a no-load status is prone to breakage as well as damages when not cooled. In the aforesaid method, between the impingement baffle and the reservoir is a horizontal configuration to have the impingement baffle operate according to the water level. However, particles formed by such method are likely to differ in size for that the water level may change easily. An impingement baffle directly attached to one side of a reservoir and a diversion method using a delivery tube have then become available recently, such that a liquid is delivered to an acting plane of internal pressure of the impingement baffle using gravity, thereby providing aerosolized medical materials from medical solutes. Yet, the medical solutes flaw the above structure by leaking and overflowing through the impingement orifices of the impingement baffle for that the medical solutes are directly flowed and spread to the acting plane of internal pressure of the impingement baffle. What is more is that in the aforesaid structure, the oscillation energy of the impingement baffle suffers significant energy losses by accepting the reverse absorption of the reserved liquid as a whole. Examples of such are portable medical nebulizers that are sold by Japan and consume substantial amounts of power.
The prior ultrasonic applications have the shortcomings below:                1. large power consumption; 5 to 28 W of power supply is required for obtaining practical aerosolization;        2. complicated in structure and bulky in size; hence inadaptable for carrying along with;        3. short impingement distance; in order to flow away rapidly, additional fans are needed for driving the aerosols produced, thus adding the size, weight as well as power consumption and noise of the mechanism;        4. low reliability; the ceramic piece therein is easily damaged by high temperatures in a no-load status (no liquid loaded thereupon), bringing consequent breakage of the ceramic, and peeling off and forming blisters of the membranes at the electroplated or silver-plated conducting terminals, or the ceramic may even lose the functions thereof when the temperature rises over the Curie temperature (point of zero charge, PTZ), which is approximately 200° C.;        5. incapable of effectively controlling the diameters of the aerosolized particles; particles with diameters between 0.5 to 5 um account for only 70% of the aerosolized particles when operating at frequencies as high as 2 to 3 MHz—it is unlikely to unify the sizes of the aersolized particles;        6. inferior efficiency of the drive circuit; the efficiency as whole only reaches n<35, wherein the conventional LC resonance circuit thereof is incapable of adjusting the operating frequency and output power thereof; in addition, full power oscillation is performed when the ceramic therein is in a light-load or no-load status in the lack of load feedback control, thus causing damages by high temperatures that cannot be totally avoided even if a temperature switch is used for protection;        7. direct contact of the ceramic piece therein with the liquid in operation in a conventional nebulizer; however, the voltage of the electrodes of the ceramic piece is above 80VAC when being operated, electrolysis and gases such as hydrogen peroxide are easily produced and then spoil the ingredient of the liquid; also, the complexity, weight and volume of the mechanism are increased for making an additional insulation;        8. the structure of common nebuizers being brittle and failing to pass the falling test of the UL Specifications; the reason behind this is that large ceramic pieces having sizes above 25 mm are preferably used for obtaining practical amounts of aerosolization; and        9. power above 5 W; certain medical properties may be changed.        